1. Field of the Invention
The present invention relates to an electrophotographic apparatus, and, more particularly, to a fuser assembly that has a selectable fuser detack mechanism.
2. Description of the Related Art
An electrophotographic imaging apparatus, such as a laser printer, forms a latent image on a surface of a photoconductive material by selectively exposing an area of the surface to light. The latent electrostatic image is developed into a visible image by electrostatic toners which contain pigment components and thermoplastic components. The photoconductor may be either positively or negatively charged, and the toner system similarly may contain negatively or positively charged particles. A print medium (e.g., a sheet of paper) or intermediate transfer medium is given an electrostatic charge opposite that of the toner and then passed close to a surface of the photoconductor, pulling the toner from the photoconductor onto the paper or intermediate medium in the pattern of the image developed from the photoconductor. After the image is transferred to the print medium, the print medium is processed through a fuser assembly where it is heated and pressed.
In a fuser assembly system, media may stick to the fuser roller. One method of detacking (i.e., separating) the media from the fuser roller to avoid a media jam in the fuser assembly is to provide detack fingers in constant contact with the surface of the fuser roller so as to strip the media from the outer surface of the fuser roller. Such an approach, however, results in increased wear of the fuser roller.
Another approach is to have a set of detack fingers positioned a predetermined fixed minimum distance away from the outer surface of the fuser roller. While this approach does not result in premature wearing of the outer surface of the fuser roller, some media, such as short grain media, recycled media, labels, may tend to slip between the detack fingers and the fuser roller, resulting in media wrapping around the fuser roller that in turn jams the fuser assembly.
What is needed in the art is a fuser assembly configured with a device to avoid media wrapping of the fuser roller, while addressing the shortcomings of the prior methods described above.